Automatically-releasing clutch



J. F. STOWE.

-AUTOMAT|CA-LLY RELEA SING CLUTCH.

APPLICATION FILED MAY 13, 1919.,

LMOM- avwawtoz 6&0206,

J. F. STD WE, AUTOMATICALLY RELEASING CLUTCH.

APPLICATION FILED MAY I3, 1919.

Patented May 11, 1920.

2 SHEETSSHEET 2.

3140a 44 fol I I M JOHN FRANKLIN STOWE, 0F LINCOLN, NEBRASKA.

AUTOMATICALLY-RELEASING CLUTCH.

Specification of Letters Patent. Patented lfl ay 11 1920.

Application filed May 13, 1919. Serial No. 296,870.

T 0 all whom it may concern:

Be it known that I, JoHnF. Srown, a citizen of the United States, residing at Lincoln, in the county of Lancaster and State of Nebraska, have invented certain new and useful Improvements in Automatically-Releasing Clutches; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This inventionrelates to automatically releasing clutches, and it relates more specifically to an improved form of clutch that is especially useful in automobile starters, and is an improvement on the device disclosed in my Patent No. 1,267,605, dated May 28, 1918, automobile-starting mechanism.

One object of this invention is to simplify and generally 'improve upon the structure disclosed in my'prior patent, by eliminating certain expensive elements and changing the form of other elements so as .to insure a quicker and more positive return of the parts to their clutching relation after being unclutched .or released from the clutching relation.

Other objects and advantages .may become apparent to persons who read the following details of description in connection with the accompanying drawings, in which :F igure '1 is a view partly in side elevation and partly in longitudinal vertical section,

the parts. in elevation not being a part of the present invention, having been shown and described in the above mentioned patent, but serving to show the relation .of the present invention to the structure disclosed in said prior patent.

Fig. 2 is a transverse vertical sectional view along the line 2-2 of Fig. 1.

Fig. 3 isa view similarto Fig. 2, but the parts being shown in a diiferent operative position. Fig. 1 is a perspective view illustrating the relative positions of' the cam and ratchet wheel on the sleeve in which the shaft rotates.

Fig. 5 is a perspective view illustrating one of the pawls which cooperate with the cam and small ratchetelement disclosed in Fig. 1.

Referring to these drawings in detail, in which similar reference characters correspond with similar parts throughout the several views, and in which the elements 1 to 16 inclusive represent parts correspondmg to those in the above mentioned patent, the invention consists in the novel construction illustrated in the parts whicha-re shown in vertical section 'in Fig. '1 and in the remaining figures. low-ever, to avoid the necessity of referring to said patent, the parts numbered 1 to 16 inclusive will now be described, briefly, as follows:

The part G represents a gear Wheel carrying a shaft which is adapted to be connected in any suitable manner to the crank shaft of an engine. The gear wheel 13 is slidable along a-sleeve 17 which is mounted to rotate freely on the shaft 3. A collar 14, a lever 15 and a link 16 constitute means for moving the gear wheel 13 into engagement with thew-heel G, it being understood that the gear wheel 13 is feather-keyed to the sleeve 17. It is also understood, of course that the shaft 3 is journaled in bearings 2 which are supported on a base 1. Members 1, 5, 6, 7, 8, 9 and 10 combine to form an actuating means whereby the shaft '3 may be rotated in the forward direction,

that is, in the direction for effecting the proper cranking movement of the engines crank shaft. However, it is to be understood that any appropriate means may be.

employed for rotating the shaft 3 forward,

and permitting it to be rotated backward under the influence of-a kick from the engine to which the member G may be connected.

The sleeve 17 has an annular shoulder or clutch element 18 secured or formed integrally thereon, and the same is formed with an annular series 19. of alternate teeth 'pawls 21 with the clutch element '18 effects the forward rotation of the sleeve 17 but when the sleeve 17 rotates backward, the gawls 21 are d1sengaged from the serles 19 by means of pins or lateral PIOjGCtlODS 23 and a double-heart cam 24. The cam 2 1is rigidly united with a ratchet wheel 25, and a pawl or dog 26 permits forward rotation of the ratchet wheel and prevents its backward rotation. The double-heart cam 24: comprises two opposite radially bulged portions 27 and two opposite radially depressed portions 28, these bulged and depressed portions combining to'form the periphery or working surface of the cam. The pawls 21 normally rest with their free ends in two oppositely disposed notches of the series 19 while their lateral extensions 23 normally rest in the depressed portions 28 of the cam, and therefore, when the shaft 3, sleeve 17 and the fly-wheel 20 are rotated forward, the cam 24 is also rotated forward, but when the parts 3, 17 and 20 are rotated backward, the ratchet wheel 25 and pawl 26 hold the cam 24 stationary so that the pins or extensions 23 ride up out of the depressed portions 28 onto the bulged portions 27, thereby releasing the pawls 21 from the notches of the sleeve 17 and permitting the latter to rotate independently of the flywheel 20. 1

Therefore, when the engine kicks, the sleeve 17 and wheel 20 start to rotate backward, but before the fly wheel has gained momentum, its pawls 21 have unclutched it from the sleeve 17, and the latter may be rotated with considerable rapidity, but being disconnected from the fly-wheel, it soon ceases to rotate, and the cranking operation may be resumed without having to wait any great length of time for the backward rotation to cease. When the backward rotation ceases, it is probable that the pawls 21 will stop with their pins 23 out of the depressed portions, and now, the coaction of the pawls 21, springs 22 and pins 23 causes the cam 24 to rotate with relation to the wheel 20, or the latter to rotate with relation to the cam 2 1 until the pins 23 again rest in the depressions 28, and now, the semicylindrical free ends of the pawls 21 will be in engagement with two correspondingly shaped notches ofthe series 19. If the semicylindrical free ends of the pawls 21 temporarily rest upon the teeth of the series 19, a slight rotary movement of the sleeve 17 will ring the pawls into engagement with the notches of the series 19, and thereby eflect a clutching engagement of the sleeve 17 and the wheel 20. r

. By comparing this improved mechanism with that which is described in my former patent, above referred to, it will be seen that I have eliminated the elements indicated therein by the numerals 19, 29, 3O and31, having 'substituted'the element 23 in the present invention for the element 30 in the former patent, thereby greatly simplifying and reducing the cost of the device, and moreover, I have substituted a double-heart- Moreover, this invention is not limited to.

the exact details of construction and arrangement of the other elements, but appropriate changes may be made within the scope of the inventive idea as described and claimed.

What 1 claim as my invention is 1. In combination with a shaft adapted to be rotated forward and backward, a sleeve on and rotatable relative to said shaft, a

oawl-carr in element on and ri id with said shaft, a pawl pivoted to said pawlcarrying element and provided with a lateral extension, a clutch element on said sleeve and engageable with said pawl to effect a clutching relation of said sleeve and shaft, and means including a cam on said shaft to press against said lateral extension of said pawl when the shaft is rotated backward and thereby annul the clutching relation of the'shaft and sleeve. 1

2. In combination with a shaft adapted to be rotated forward and backward, a sleeve on and rotatable relative to said shaft, a pawl having a lateral projection, means connecting the pivot of said pawl to said shaft, means on said sleeve to engage with said pawl and thereby effect a clutching relation of said shaft and sleeve, and a cam comprising a radially bulged portion and a radially depressed portion and being mounted for forward rotation about the axis of said shaft, thelateral projection of said pawl being normally engaged with said depressed portion to effect the forward rotation of the cam, said bulged portion of the cam being adapted to coact with said lateral projection in disengaging said pawl from said sleeve when the latter is rotated backward.

3. In combination with a shaft adapted to be rotated forward and backward, a sleeve on and rotatable relative to said shaft, a pair of spring-pressed pawls each provided with a lateral projection, means connecting the pivots of said pawls to said shaft at 0pposite sides of the latter, means on said sleeve to engage with said pawls and thereby efiect a clutching relation of said shaft and sleeve, and a cam comprising two opposite bulged portions and two opposite depressed portions, the latter normally engaging with said lateral projections and coacting therewith to effect a forward rotation of the cam, return the pawls to their engaging relation said bulged portions being cooperative with with said sleeve, the points of pressure of said lateral projections to simultaneously the pawls being at diametrically opposite 10 disengage the pawls from said sleeve when sides of the shaft and sleeve.

the latter rotates backward, said spring- In testimony whereof I have hereunto set pressed pawls being adapted to press upon my hand.

said opposite bulged portions and thereby JOHN FRANKLIN STOWE. 

